I found this on "Portable Freeware":
"...Generally, PortableApps.com releases updates to Thunderbird within about 24 hours for the 2 dozen packages supported. Thunderbird Portable 68.x was purposely delayed while we implemented a fix for extension portability and the 60.x branch was maintained. That way users didn't suddenly have all their extensions break. It's nearly complete but was delayed while I recovered from an illness. The other package you mentioned breaks extensions as it is moved and is using Mozilla's trademarks by repackaging Thunderbird in violation of their trademark guidelines..."
Is John all right? I hope he didn't get sick with that "C" thing?